The present invention relates to tool arm assemblies of the character disclosed in U.S. Pat. Nos. 3,190,152; 3,812,747; and 3,232,153, and more particularly to certain novel and important improvements therein which increase the accuracy and reliability of such tool arm assemblies. Tool arm assemblies of this type adjust for wear of the tool in use and constructions such as shown in U.S. Pat. Nos. 3,877,329 and 3,793,708 provide for replacement of the cutter.
The present assignee's prior patent 3,812,747 discloses a remotely controlled tool arm assembly where a cam is utilized with a stepping motor to incrementally advance the tool bar and tool via a follower arm. The present tool arm assembly, wherein a remotely controlled tool bar position adjusting mechanism is utilized which is manually overridable, is considered to be a significantly improved mechanism for transmitting precise incremental motions with dependable accuracy in the range of several ten thousands of an inch.
One of the prime objects of the present invention is to provide a remotely controlled, mechanically operated, manually overridable tool arm assembly which avoids the use of stepping motors.
Another object of the invention is to provide a tool arm assembly of this character which is rugged, very serviceable, and more economical to manufacture.
Still a further object of the invention is to provide a tool arm mechanism of the character described which accomplishes motion transmission in a manner to avoid the possibility of a back-lash error.